Base Idle, Fast Idle, Non Idle - Best Practices Diesel

dons2346 wrote:
There is nothing in my Cummins manual that says to go to fast idle as soon as you start it.

As far as I am concerned, fast idle is there for nothing more than to piss off your neighbors while you bring in the slides, talk to your friends, unhook the water, talk to your friends, unhook the sewer, talk to your friends, hook up the toad, and say good by to your friends

That's a great point. I think you once mentioned that you have an '02. The world has changed dramatically in the past 14 years. Tolerances are much lower, alloys have changed, fluids are reformulated, computers control every operation of the engine and the SCR emissions systems demand high heat to operate effectively.

Best Practices are surely different for older engines, vs newer engines.

There is nothing in my Cummins manual that says to go to fast idle as soon as you start it.

As far as I am concerned, fast idle is there for nothing more than to piss off your neighbors while you bring in the slides, talk to your friends, unhook the water, talk to your friends, unhook the sewer, talk to your friends, hook up the toad, and say good by to your friends

holstein13 wrote:

WILDEBILL308 wrote:
You must have a miraculous air pump. You can't get underway until you have enough air pressure to release the parking brake.

No miracle air pump, but I often have enough air pressure from before I shut down. My coach has air leveling and if I'm stopping overnight, I don't purge the tanks and dump the air. Furthermore, when I stop at a rest stop or restaurant while traveling, I don't purge my tanks either. So yes, absolutely, I can get going in 10 seconds and have enough air pressure to release the parking brake. While I do listen for the spitter before going forward, I also have a backup low air alarm and it doesn't usually go off at all unless I've purged the tanks to put down the jacks the night before. It's really not that mysterious.

If you have air bag leveling you have a electric air compressor that keeps your air pressure up.
Most coaches have to use the engine powered compressor to build air pressure.
Bill

Not hard to understand. When you start a cold engine and after oil pressure comes up when you go to fast idle the additional boost provided generates enough heat to get more complete combustion of the fuel.

"But here's what Cummins told me directly. My engine has a warm up protection feature that won't allow me to fast idle or use the throttle until the engine is ready to perform and everything is up to pressure and temperature to prevent harm. This is what's coming directly from Cummins."
Well that is easy to check. I bet starting with a cold engine, as soon as you can go to fast idle you can drive. It won't be at operating temperature.
Bill

holstein 13, There is always the option of moving to Yuma Arizona in the wintertime to keep your engine warm or putting the engine heater on a timer about 2 hours before you plan to start it. :)

WILDEBILL308 wrote:
The facts behind this not theory are the cold engine will not burn all the fuel and it will wash down the cylinder walls(creating excessive wear)and contaminate/dilute the engine oil.

I'm glad you brought this up because I really don't understand how to avoid this at all. How do you get your engine warm without first having a cold engine that's burning fuel inefficiently? This makes no sense and it's a catch 21. If I read the comment correctly, a cold engine at idle will burn inefficiently and will wash down the cylinder. The cure is a warm engine, but to get to the warm engine, you need to burn fuel inefficiently with a cold engine.

I guess what I'm saying is that no matter what you do, your engine is going to be cold for a certain period of time and there is nothing you can do about that except to avoid starting and stopping your motor to let it cool down too often. You can't let it idle either because Cummins says that's the worse thing you can do to an engine.

But here's what Cummins told me directly. My engine has a warm up protection feature that won't allow me to fast idle or use the throttle until the engine is ready to perform and everything is up to pressure and temperature to prevent harm. This is what's coming directly from Cummins. This afternoon, I spoke to the tech myself to understand this. Once the engine is warmed up, the engine should be in fast idle when parked.

So the two worse things you can do to your engine are 1) start it cold and 2) let it idle. Talk about confusing.

WILDEBILL308 wrote:
You must have a miraculous air pump. You can't get underway until you have enough air pressure to release the parking brake.

No miracle air pump, but I often have enough air pressure from before I shut down. My coach has air leveling and if I'm stopping overnight, I don't purge the tanks and dump the air. Furthermore, when I stop at a rest stop or restaurant while traveling, I don't purge my tanks either. So yes, absolutely, I can get going in 10 seconds and have enough air pressure to release the parking brake. While I do listen for the spitter before going forward, I also have a backup low air alarm and it doesn't usually go off at all unless I've purged the tanks to put down the jacks the night before. It's really not that mysterious.

MM.Thanks for the update. Very interesting how Cummins and Detroit Diesel approach this differently. I think I like the Cummins approach better because you can basically get moving within 10 seconds of starting the engine.

You must have a miraculous air pump. You can't get underway until you have enough air pressure to release the parking brake.
6 pages of people all who ignore the two people who told you the proper procedure. I love the responses from people who have so much money they don't care if they are doing something that is damaging to their motor. The only one not heard from is someone who starts his engine and holds it at 2500+ to warm it up.
Now the original question was.
"What are best practices for idling and what are the theories behind them", not how fast can I drive away.
The best practice, according to Cummins and it matches what I have heard from Cat. When starting a cold engine you should go to fast idle as soon as the oil pressure comes up. The facts behind this not theory are the cold engine will not burn all the fuel and it will wash down the cylinder walls(creating excessive wear)and contaminate/dilute the engine oil.
The next thing is it creates carbon build up on injectors valves rings and can lead to injector failure and loss of performance.
If it is cold out your engine will never reach full operating temperature at low idle.
Now if you want to get underway quickly... Well go back and read what wolfe10 has posted I don't feel like re typing it.
Bill

Holstein13, these things are just too electronic! In a good way! LOL!

As long as we can get down the road enjoying our camping experiences, that's all that counts!

MM.

I just found an interesting piece of information on Cummins Engine Warm up protection:

"Engine Warm-up Protection - This feature inhibits the throttle to keep the engine at low idle for a brief period after the engine starts to allow oil to reach all critical areas until engine components before speed is increased above low idle.

To limit the engine's speed at start-up, the following inputs are limited:

1. Throttle input
2. Intermediate-speed control switches
3. Datalink control inputs.

NOTE: The maintenance lamp is turned on while this feature is operating. Once adequate oil pressure is attained, the lamp is turned off.

The engine warm-up protection feature can be enabled or disable with the INSITE™ electronic service tool."